HD64F2168 Datasheet, PDF (659/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

2. Download of on-chip program
The on-chip program is automatically downloaded by setting the flash key code register
(FKEY) and the SCO bit in the flash code control status register (FCCS), which are
programming/erasing interface registers.
The flash memory is replaced to the embedded program storage area when downloading. Since
the flash memory cannot be read when programming/erasing, the procedure program, which is
working from download to completion of programming/erasing, must be executed in the space
other than the flash memory to be programmed/erased (for example, on-chip RAM).
Since the result of download is returned to the programming/erasing interface parameter,
whether the normal download is executed or not can be confirmed.
3. Initialization of programming/erasing
The operating frequency is set before execution of programming/erasing. This setting is
performed by using the programming/erasing interface parameter.
4. Programming/erasing execution
For programming/erasing execution, the FLSHE bit in STCR and the FWE pin must be set to 1
to transition to user program mode.
The program data/programming destination address is specified in 128-byte units when
programming.
The block to be erased is specified in erase-block units when erasing.
These specifications are set by using the programming/erasing interface parameter and the on-
chip program is initiated. The on-chip program is executed by using the JSR or BSR
instruction and performing the subroutine call of the specified address in the on-chip RAM.
The execution result is returned to the programming/erasing interface parameter.
The area to be programmed must be erased in advance when programming flash memory.
All interrupts are prohibited during programming and erasing. Interrupts must be masked
within the user system.
5. When programming/erasing is executed consecutively
When the processing is not ended by the 128-byte programming or one-block erasure, the
program address/data and erase-block number must be updated and consecutive
programming/erasing is required.
Since the downloaded on-chip program is left in the on-chip RAM after the processing,
download and initialization are not required when the same processing is executed
consecutively.
Rev. 3.00, 03/04, page 619 of 830